SCRUPARIi^ CLAVATA. 25 



Zoarium sparingly branched. Zooecia sometimes uni- 

 serial, sometimes in two series placed back to back_, 

 elongate, clavate, rounded at the top and attenuated 

 downwards; each cell attached to the dorsal surface of the 

 one below it, at some distance from the top, by a cordate 

 expansion of the base ; aperture suborbicular, slightly 

 produced and contracted below, not marginate. Ooecia 

 globose, with a few rather large punctures. 



Range of Variation. I have noticed the principal variations 

 to which this species is liable in the remarks on the 

 genus, and shall merely add the following detailed obser- 

 vations by way of illustration. 



1 . A line of eleven cells ; from the third above the base, 

 a branch given off, and also from the sixth. Immediately 

 below the higher branch a pair back to back, and imme- 

 diately above it a pair, then an ovicelligerous cell. Also 

 a pair immediately below the top cell. 



2. A line of about seven cells ; at the top two pairs 

 back to back, and four ovicelligerous cells, two on each 

 side, so that the shoot at this point exhibited four rows of 

 cells. 



3. A normal cell at the base, then two pairs back to back, 

 and an ovicelligerous cell at one side on the line of 

 junction. 



4. A long line of cells, the third being of the shorter 

 form, and this alone having another cell back to back 

 with it. 



5. A line of seven cells ; the fourth and fifth giving off 

 cells at the back. 



6. A normal series, with one or two ovicelligerous cells 

 at intervals on the dorsal surface. 



Habitat. On other Polyzoa in shallow water. 

 Localities. Lamlash Bay, Arran; Filey Bay, off the 

 Brigg, chiefly on Crisidia cornuta, abundant ; on Cellulai'ia 



